This invention relates to filter devices; and more particularly relates to replaceable filters for liquid containers, particularly water, and to a novel and improved means for monitoring the number of uses of the filter.
There is increasing popularity and demand for filtered drinking water and, both in home and offices, water dispensers are in use which require a replaceable filter to remove contaminants from the water. In the past, typically the approach has been to monitor the number of times that the same container is filled with water and then filtered but are not capable of monitoring the number of times that each filter is placed on a different bottle. Nevertheless, in most widespread use both in the home or office are water services of the type in which the container, once empty, is replaced by another container filled with water or at least requires removal of a cap in order to refill the empty container. Accordingly, there is a need for a filter use limitation device in which the number of times that the filter is used is correlated with the number of times that it is removed and replaced onto one or more containers.
Representative prior art patents are U.S. Pat. No. 5,190,643 to Duncan et al, U.S. Pat. No. 5,328,597 to Boldt, Jr. et al, U.S. Pat. No. 5,536,394 to Lund et al and U.S. Pat. No. 5,299,701 to Barker et al.